The present invention relates to sealing rings, and in particular sealing rings in gas turbine engines.
It is common in gas turbine engine rotor assemblies to find annular gaps disposed between co-axial rotatable members. In use, many of these gaps require sealing in order to prevent leakage of high pressure gases into low pressure regions.
In gas turbine engines, it is known to use piston type sealing rings located in circumferential grooves machined in the surface of the inner shaft member to control such leakage. Conventional sealing rings having a rectangular toroidal section and an overlapping scarf joint, the plane of which is disposed parallel to the radial surfaces of the ring, have however, in sealing arrangements of this type, proved to perform less than satisfactory. During operation, that is under the influence of rotational loading, the sealing ring expands outwardly, eventually being restrained by the internal surface of the outer member, resulting in a leakage path being created through the expanded scarf joint.
Additional leakage can also occur with this conventional type of sealing ring unless a costly zero axial clearance fit is maintained between the ring and the groove.